Bartlett's Familiar Quotations (10th Edition) - http://www.bartleby.com/quotations/
Search three quotation collections: Bartlett's Familiar Quotations (1919), Columbia World of Quotations (1996), and Simpson's Contemporary Quotations (1988). Contains over 86,000 well known quotes.
The Word Spy - http://www.wordspy.com
This Web site is devoted to defining recently coined words, existing words that have enjoyed a recent renaissance, and older words that are now being used in new ways.